import React, { Component } from 'react'
// 引入store，用于获取redux中保存的状态
import store from '../../redux/store'
// 引入actionCreator，专门用于创建action对象
import { createIncrementAction, createDecrementAction } from '../../redux/count_action'

export default class Count extends Component {

  componentDidMount() {
    // 检测redux中状态的变化，只要变化，就调用render
    store.subscribe(() => {
      //  只要reudx里保存的任何一个状态发生改变，就调用该回调
      // console.log('@')
      this.setState({})
    })
  }

  // 加法
  increment = () => {
    // 获取用户输入
    const { value } = this.selectNumber
    store.dispatch(createIncrementAction(value * 1))
    // store.dispatch({ type: 'increment', data: value * 1 })
  }

  // 减法
  decrement = () => {
    // 获取用户输入
    const { value } = this.selectNumber
    // store.dispatch({ type: 'decrement', data: value * 1 })
    store.dispatch(createDecrementAction(value * 1))
  }

  // 奇数再加
  incrementIfOdd = () => {
    // 获取用户输入
    const { value } = this.selectNumber
    // 读取原来的状态值
    const count = store.getState()
    if (count % 2 !== 0) {
    //   store.dispatch({ type: 'increment', data: value * 1 })
    store.dispatch(createIncrementAction(value * 1))
    }
  }

  // 异步加
  incrementAsync = () => {
    // 获取用户输入
    const { value } = this.selectNumber
    setTimeout(() => {
        store.dispatch(createIncrementAction(value * 1))
    //   store.dispatch({ type: 'increment', data: value * 1 })
    }, 500)
  }

  render() {
    return (
      <div>
        <h1>当前求和为：{store.getState()}</h1>
        <select ref={c => this.selectNumber = c}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>&nbsp;
        <button onClick={this.increment}>+</button>&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;
        <button onClick={this.incrementIfOdd}>当前求和为奇数再加</button>&nbsp;
        <button onClick={this.incrementAsync}>异步加</button>
      </div>
    )
  }
}
